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Information about the Apollo CPU and FPU.

Apollo & Specific Processor Emulation / MMU

Mack B Wallace

Posts 2
08 Mar 2016 17:45


I'm curious, does the Apollo emulate a specific model of the 68k processor, or is it an implementation that is more of a cross section of the entire family (i.e. emulates op codes from across the entire family of 68k processors)? …or does the Apollo emulate a MMU?

My knowledge of the 68k architecture is very limited. But from what I understand, the MMU in the 68030 is significantly different from the MMU in the 68040. This is noticeable for me as I like to run Amiga Unix on my A3000, and from what I understand Amiga Unix will not run on an 040 due to the differences in the MMUs. So there is no accelerator option for me unless I can find a 68030@50 MHz - which seem to be rather rare. So the idea of something that could fully emulate a 68030 while running significantly faster than 50MHz intrigues me.


Gunnar von Boehn
(Apollo Team Member)
Posts 4519
08 Mar 2016 18:47


Mack B Wallace wrote:

I'm curious, does the Apollo emulate a specific model of the 68k processor, or is it an implementation that is more of a cross section of the entire family (i.e. emulates op codes from across the entire family of 68k processors)? …or does the Apollo emulate a MMU?
 

Apollo does not emulate, Apollo is a genuine 68k CPU.

Regarding instructions:
Apollo supports a super-set of 68k-instructions.
Apollo is software compatible to 68000/68020/68030/68040/68060.
Apollo also offer a number of new, advanced instructions which no 68k CPU ever had.

MMU:
At the moment no MMU is provided with Apollo.
As an MMU is not needed for AMIGA-OS, the MMU was so far not high Priority for us.
Technically supporting a fully 68040 compatible MMU would be no problem at all.




John William

Posts 460
08 Mar 2016 21:50


I hope people realize that FPGA is never emulation...it is a genuine thing! Let us go back 30 years or less...when Motorola was making their famous Motorola 68K CPU.. I am sure when they made the shape rectangular (famous Amiga 500/2000/1000 CPU) it was empty in the inside...somehow somewhere they had to program the CPU as they programmed Agnus, Paula, etc. You don't magical pop a programmed chipped by a push of a button...you need "software" and hardware to work together to run the hardware (I quoted the software part). Even the first computer in the world with the light bobs or whatever was put in a programmed way to function. Point is...this is genuine and not emulation and I look at Vampire is a pure real Amiga accelerator and my Amiga is real Amiga after installing it. I just....upgraded parts on the Amiga that needed upgrading that is all.

Same when a new stand alone FPGA hardware shows up..it too is a real Amiga.


Roman S.

Posts 149
09 Mar 2016 16:17


AFAIK the WHDLoad can profit from the MMU - so this would be a welcome addition for a lot of users.


Johannes Schäfer

Posts 47
12 Mar 2016 13:38


AFIK the MMU is not used in AMIGA OS. Instead, in the past it slowerd the CPU by 20% only for being there. So Commodore build most Amiga´s without MMU, even the A4000-EC-030.

So, if the Apollo Team finds a way to provide the MMU without slowering down the CPU so much, or if they provide two cores, with and without MMU, then do whatever you want.

I dont want an MMU in my Amiga, then it´s not an Amiga.


John William

Posts 460
12 Mar 2016 22:42


Johannes Schäfer wrote:

AFIK the MMU is not used in AMIGA OS. Instead, in the past it slowerd the CPU by 20% only for being there. So Commodore build most Amiga´s without MMU, even the A4000-EC-030.
 
  So, if the Apollo Team finds a way to provide the MMU without slowering down the CPU so much, or if they provide two cores, with and without MMU, then do whatever you want.
 
  I dont want an MMU in my Amiga, then it´s not an Amiga.

Having an MMU or not having it does not make what you have an Amiga or not an Amiga. Same if you have an fpu or not an fpu. However, with one thing I like about your sentence is this: Have two versions of cores is not a bad idea.


posts 6